Limited cut-off locomotive and method of operation



Oct. 11, 1932.

w. E. WQQDARD LIMITED CUT-OFF LOCOMOTIVE AND METHOD OF OPERATION 5 Sheets-Sheet. 1

Filed Jan. 7. 1927 Oct. 11, 1932.

w. E WOODARD ,310

LIMITED CUT-OFF LOCOMOTIVE AND METHOD OF OPERATION Filed Jan. 7, 1927 5 Sheets-Sheet 2 9513/6/ Qua/MW A Oct. 11, 1932. w. E. WOODARD LIMITED CUT-OFF LOCOMOTIVE AND METHOD OF OPERATION Filed Jan; 7. 5 Sheets-Sheet 5 Oct. 11 1932. w. E. wobnARn LIMITED CUT-OFF LOCOMOTIVE AND METHOD OF OPERATION Filed Jan. 7. 1927 5 Sheets-Sheet 4 -l ll Oct. 11, 1932. w. E. WOODARD LIMITED CUT-OFF LOCOMOTIVE AND METHOD OF OPERATION 5 Sheets-Sheet 5 Filed Jan. 7. 1927 Patented Oct. 11, 1932 UNiTEi-Ii STATES WILLIAIVI E. \VOODARD, OI FOREST HILLS, NEW YORK,

LIMITED CUT-OFF LOCOMOTIVE ANDMETHOD OF OPERATION.

Application, filed January 7, 1927. Serial No. 159,618.

This invention relates to locomotives and particularly to that type which has new become known in the art as a limited cut-off locomotive. It also involves a new method of operating a locomotive.

The nature and objects of the invention will be more clearly understood and ap pre'ciated if the following facts are kept in mind. It is a well recognized fact that if the maximum cut-off is limited to a point which is substantially less than normal, a pronounced saving in steam consumption can be effected per unit of work. For instance in heavy freight service with a locomotive limited to a 60% maximum cut-off there is in the neighborhood of a to saving in steam consumption as compared with former practice where the average normal maximum cut-off was around 85%. It follows that the shorter the maximum cut-off can be made the greater will be the saving because of the greater expansive use of the steam.

However, with the arrangements heretofore relied upon it is not practicable to set the 3 maximum cut-oif below a well defined limit because of the fact that the engine may stop with the cranks in such positions as will prevent the entry of steam to the cylinders at starting or, if admitted, will reduce the turning moment to such an extent that it will not be sufiicient to get the engine in motion.

WVith the customary valve arrangements met with in standard practice where there is no particular method of delivering steam to the cylinders at these disadvantageous posipointed out, it is highly desirable to use even shorter maximum cut-offs than the foregoing and it is the principal object of my invention to provide means for limiting the maximum cut-off to any desired point while at the same time providing for sure and prompt starting of the locomotive at any? position; of the cranks.

1 His also aniobjectaoftmy'inventionto provide, in a limited outwit: locomotive, a means for automatically lengthening the cut-off when starting the locomotiveand subsee quently returningit automaticallytoithe prodetermined limited maximum cut-01f" A further object of the invention resideszin". iZlIG'PI'OVIlSlOHiOfZ means for subjecting on subordinating the said automatic." features ztl)" the control of the? pressure. in: the locomotive steam chests'in' connection: with which I are range for the lengthened cuteoif until such time as the steamv chest pressurerrises 'toaa predetermined point;

Still another: object" of the invention? is to make the foregoing: automati'cfapparatusisub ordinate to-the position of the: reverse. gear or some moving. part associated therewith. In other words I- provideiforanz arrangement of the parts whereby'tlie lengthened cut-oft is possible'only when ina maximumlimited cut-offposition.

I also propose a: method of operatingz'a; limited cut-oif locomotive which invoives lengthening't'he cut-elf. beyond the predeter mined limit whenever the steam. chest; pres; surei's below a certain predetermined stand; ard but" returning it" to the limit whem said pressure is above said standard.

My invention also contemplates the pro"- vision of means for and theoperation ofa locomotive whereby the cut ofl will balengthened automatically when the steam: chest pressure is belbw a predetermined standard and subsequentlyshortened should the pres sure rise above said standard.

The foregoing'toge'ther" with such other objects as are incident to my invention or which may appear hereinafter are" obtainedby means of a constructionwhich is illustrat ed in preferred form inthe accompanying drawings, wherein Fig. 1 is a side elevation of a locomotive with my invention applied thereto Fig; l'a-isa view similar to that of Fig: 1 but showing only the principal parts of my invention in a purely diagrammatic m'anner;

Fig. 2 is an enlarged side elevation of apart 2 0 I i tinctly of the apparatus utilized in carrying out my invention with certain portions illustrated in section;

Fig. 2a is a fragmentary view of a portion of the structure shown in Fig. 2 but illustrating a modified arrangement of the parts to be described hereinafter.

Fig. 3 is a section on the line 3-3 of Fig. 2;

Fig. 4 is a section thru a part of my improved apparatus;

Fig. 5 is a view similar to that of Fig. 2 but illustrating a modified arrangement of certain of the parts;

Fig. 6 is a side elevation of Fig. 5 looking from the left; and

Fig. 7 is a section on the line 77 of Fig. 5.

- In the following description it will be as sumed that the normal maximum cut-0E desired is although I wish it to be disunderstood that my invention is equal y applicable to any other setting such, for example, as a 10% setting or a set ting.

With my invention the locomotive A can be equipped with any desired type of valve gear B. In the present instance what is well known in the art as a Baker gear is illustrated, but it will not be described in detail because its function and mode of operation are well known to those skilled in the art and, further, because my invention does not involve any improvement therein. Suflice it'to say that by means of the reverse gear 11 (which in this instance is shown as a power reverse gear although it need not necessarilybe such) with its operating wheel 11a -'it .is possible to adjust the valve gear B so that it will give any desired cut-off for the valves up to the predetermined maximum above referred to. But before entering upon the customary detailed description of the, accompanying drawings it is desired to direct attention in the first instance to the diagrammatic Figure 1a which illustrates the essentials of my invention as simply as possible. In this figure I have represented the reverse shaft by the circle at 7 ,the reverse shaft arm by the line at 6, and the reach rod between the reverse gear 11 and the reverse shaft arm by the line at 10. The line 1 indicates the rod which connects the end of the reverse shaft arm 6 to the reverse yoke 2 of the valvegear structure B, 12 representing the pivot betweenthe arm 6 and the rod 1. In carrying out myinvention I make the point 16 where the reach rod 10 is coupled to the reverse shaft arm 6 a sliding connection in the slot 13 so that it may be moved toward or away from the pivot 12-.

For normal running conditions I arrange (as will appear in more detail later) to keep the point 16 at the top of the slot 13. The other end of the reach rod 10 is pivoted at 13 e to the piston rod or cross head of the power reverse gear 11 and the various parts are so connected or correlated under normal running conditions as to make the position 6 of the reverse shaft arm 6 the position farthest in the corner, as it is colloquially expressed. But this position isarranged to give only a limited maximum cut-off, say 50%, according to our assumption. However, as explained, with this cut-0H it might be impossible to start the locomotive so I provide mechanism (to be described below) for automatically lowering the point 16 to the point 16' in the slot 13. IV hen this takes place, with the point 43 stationary as it will be, the reach rod 10 will assume the position 10, the reverse shaft arm the position 6", and the rod 1 the position 1, and the valve gear B will then be moved to set the valves for a long cut off, say or so that the locomotive can be started. As soon as a start is made the point 16 is automatically returned to its upper position in the slot 13 which corresponds to a 50% maximum cutoff (according to our assumption). The description has been for forward running but 1 the operation would be exactly the same in reverse except that the reverse shaft arm would be moved to left of its neutral position 6.

\Vith the foregoing rather brief description and analysis in mind I will now describe the details of my invention in its herein disclosed embodiments reference being made to but one side only of the locomotive since many of the parts are simply duplicated on the other side.

The locomotive A is provided with the customary valve chamber or steam chest 3, cylinder 4 and steam pipe 5.

The reverse shaft arm 6 is formed with a suitable hub portion 66; for surrounding the shaft 7 and is keyed thereto. The shaft in turn is mounted in the bearing 8 which is supported from the bracket structure 9.

The reverse shaft arm 6 is moved by means of the reach rod 10 which can be connected either to the customary reverse lever in the cab of a locomotive or to the power reverse gear 11 as illustrated in the present application. The effective throw of the reach rod 10, insofar as its effect upon the valve gear B is concerned, is determined by the point of its connection to the arm 6 and as shown and already briefly described the reach rod 10 is connected to the arm 6 at a point intermediate the connection 12 of the rod 1 at the top and the reverse shaft 7. In other words, for any given amount of movement of the reach rod 10, the effect upon the valve gear B will be less if its connection to the arm 6 be at a point near the pivot 12 than if said connection were at a point near the shaft 7.

I arrange for a variable connection between the rod 10 and the arm 6 by providing the arm .6 with a slot 13 in which slides a block 14. The end of the reach rod is forked as at so that it can embrace the arm 6 and the block 14.

the cranks with such a maximum cut-off.'

Therefore, in order to start the locomotive I make arrangements for moving the reverse shaft arm 6 from position 6 to the position 6 in Fig. 2. The details associated with this will now be described. But before going ahead with this it might here be stated that the position 6 can be made to correspond, for example, to about 70% maximum cut-off, but neither this percentage of cut-off nor that which exists when the lever 6 is in its 6 position, namely, 50% under our assumption, are intended to be the upper and lower limits of my invention. By changing the length of the slot 13 or the height of the arm 6 or in many other ways altering the relation of the parts, any desired cut-offs can be provided for.

Inasmuch as for normal average running conditions it is desired and intended to have only a 50% maximum cut-off, I provide means for holding the block 14 in its upper position as illustrated in Fig. 2. Directly below the block and mounted on the arm 6 so that it will be carried therewith I provide a cylinder 17 the piston 18 of which is connected to the'block 14 by its piston rod 19. This piston is a double acting one and fiuId pressure, preferably air, can be dehvered to either side thru the flexible pipes 20 and 21,

the former delivering the pressure to the lower face of the piston and the latter to the upper face as clearly shown in Fig. 3. Certain valve mechanisms indicated as a whole by the character C control the fluid pressure in the manner now to be described.

A slide valve 22 in the casing 23 is normally held in position to exhaust the pressure from the upper side of the piston thru the pipe 21, cavity 24 and exhaust port 25 and to admit pressure to the lower face of the piston thru the pipe 26, Valve chamber 2. port 28 and pipe 20, the pipe 26 being connected to any suitable source of a1r pressure on the locomotive such as the reservoir 29. The valve is moved by means of the piston mechanism 30 which is normally held in its right-hand position (see Fig. 2) by means of the spring 31. The rod 32 of this piston enters the valve chamber 27 and is provided with the lugs 33 for engaging the valve It also carries a valve member 34 which ;-is adapted to seat against the end wall 35 in order to prevent leakage .ofair around-the stem 32 when the piston ,30-isin its righthand position. A similar valve'face :36 is provided at the opposite end of thestem 132 in order to prevent leakage therealong when the piston is in its left-hand position to be dereach rod 10 will'be limited to the maximum cut-off desired-under our assumption 50%.

Let us assume now that it is desired to start the locomotive. With the 50% maximum cut-ofl' this might be impossible in certain positions of the cranks. that when the reach rod 10 has been manipulated by the engineerto give the 50% maximum cut-off referred to either by means of a hand reverse gear or by meansof the power reverse gear 11 illustrated herein,the piston 18 will move the block 14 to its lower position. This action will cause the arm 6, al ready moved to the position 6, to move still further toward the right to the position 6". When in the position 6 the head of a bolt'37, carried by the arm 6, will be brought into engagement with the plunger 38 as indicated in dotted lines in Fig. 2. The plunger mechanism will then move downwardly to close the valve 39 and open the valve 40 so that fluid pressure can enter thru the pipe 41 and pass over to the piston 30 thru the port 42 The piston 30 will then move to the left in order to cut off the supply of fiuidpressure to the underface of the piston 18 and open the pipe 21 leading to the upperface of the piston 18. This action will immediately pull the block 14 down and withfit the end of the reach rod 10, the latter being pivoted at 43 to permit of this motion. The pipe 41 is supplied with fluid pressure from any suitable source on the locomotive such as the reservoir 44.

But the flow of fluid pressure to the pipe 41 is subject to an additional control which ..1

forms an important part of my invention and which will now be described.

In the pipe 41 is a valve mechanism indicated as'a whole by the characterD. By referring to Fig. 4 it will be seen that this mechanism includes a valve 45 which is adapted to be closed by the piston'47 upon accumulation of sufficient pressure thereabove to overcome the resistance of the spring 48 and the pressure of the fluid below the valve 45.

The valve 45 in the absence of sufficient steam pressure is normally in its open position because the entrance. to the port 49 leading to the piston 47 is normally closed bytlie .1

I therefore arrange 5' 52 the under face of which is connected by the-pipe 53- to the steam pipe 5. The diaphragm 52 is therefore subject to the live 'steam pressure going to the steam chests or in other words to the steam chest pressure.

At this point, in order to more clearly understand the invention, it is necessary to describe the manner in which a locomotive is started. As is well known in the art the engine throttle is never suddenly opened to its full extent. Instead the throttle is but slightly opened in order to admit a limited amount of steam to the cylinder until the locomotive has taken up the slack of the train and the driving wheels begin to revolve. After the slack has been taken up the engineer may open the throttle to its full extent thereby supplying full steam pressure to the cylinders. The reason for this method of starting a locomotive is because if the throttle were instantly opened wide the locomotive might start forward with a sudden lurch with the result that train couplings would be broken or torn apart or other serious damage occur.

The average working pressure, let us assume, is 250 lbs. although higher boiler pressures are now not uncommon. I make the power of the spring 51 sufiicient to counterbalance a pressure of approximately 200 lbs. so that it is necessary for the pressure below the piston 52' to rise slightly above that point before the needle valve 50 will be opened and the piston 47 moved downwardly to close the valve 45. In this way I make my improved apparatus directly and automatically responsive or subordinate to steam chest pressure for whenever the pressure in the steam chest is below a certain predetermined point say, for example, the 200 lbs. mentioned, the air pressure can flow past the valve 4:5 to the mechanism '0 already described so that the normal maximum 50% cut-off will be in creased to say or This will enable ready starting of the locomotive. But just as soon. as the engineman opens the throttle to its full extent as previously described, the pressure will rise above the predetermined point and the air pressure will be shut off thru the pipe 41 and the mechanism C will operate to move the block lt upwardly and restore the normal 50% limited maximum cut-off.

As will be seen the mechanism C in the embodiment illustrated is subject to two separate controlling devicesthe valve D which is in the nature of a pilot device, and the parts 37, 38, 39 and 40 associated with and dependent upon the position of the reverse shaft arm. With this arrangement. the mechanism D can perform its function only when the reverse arm6 is in its 50% maximum cut-off position.

In order to permit motion of the arm 6 tothe position 6 the plunger 38 is yieldingly held by the spring 54.

Figs. 5 to 7 inclusive illustrate a modification wherein the operating piston for the reach rod 10 is composed of alarger portion 18a and a smaller portion 18?). Pressure is normally applied at all times to the face of the smaller piston thru the pipe 26a so that the reach rod 10 will be held in the upper position in the slot 13. When the valve 39 is closed and the valve 40 opened by the action of the arm 6 and bolt 37 operating upon the plunger 38, air pressure from the pipe ll will be admitted to the upper or larger piston 18a and thereby force it downwardly against the pressure on the smaller area of the piston 18?). This will move the reach rod 10 downwardly and force the arm 6 from the position 6 to the position 6 exactly in the manner already described in conn ect on with the other figures. It will be noted in Figs. 5 to 7 inclusive that the cylinder 17a with its pistons 18a and 18b and piston rod 19a are located just back of the point 16 instead of directly under it as in the other figures. This, however, is a mere matter of design and is illustrative of the different ways in which my invention may be embodied.

In conclusion I wish to point out that by omitting the control exercised by the reverse shaft arm 6 parts 37, 38, 39 and l0) it is possible to make the block 14 directly responsive to variations in the steam chest pressure irrespective of the position of the reverse gear and this might be done, of course, in either forward or backward running of the locomotive. The necessary arrangement of parts for accomplishing this is shown in 2a.

Pipe 41 is vented through a leakage groove 45a, a vent i866 and exhaust ports 55 and 56, while the valve L5 is in its closed position. In this way, whenever the steam chest pressure is below a certain predetermined standard the locomotive will operate at a proportionately longer cut-off for a given setting of the reverse gear. But when the pressure in the steam chest is at or above the predetermined standard the cut-ofi will be less for a given setting of the reverse gear by the proportion made possible through the use of the variable connection in the slot 13.

A brief summary of the operation will now be given.

In the first place, let us assume that the locomotive is being started in a forward direction from a dead stop and that equipment including the parts 37 38, 39, and 40 shown in Fig. 2 has been adopted. When the 10- comotive is standing still the pressure in the steam chest is approximately atmospheric pressure. The engineer first actuates the reverse gear 11'to move the reverse shaft arm 6 to the position 6. VJ hen this position is attained the bolt 37 will depress the plunger 38:, close the 'valve 39, and open the valve 40 ,so that communication is established bewillbeno pressure above the piston 47 so that the spring 48 will act to move it upwardly and" thereby open the valve 45. Air pressure will then flow from the reservoir 44 through the pipe 41 to the right hand face of the piston30, and the piston 30 as a consequence will be forced to the left, carrying with it the control .Valve 22. r 'VVhen this occurs the air pressure entering the valve chamber 27. through the pipe 26 will be admitted to the pipe 21 leading to the upper side of the piston 18 in the operating cylinder 17. At the same time the pressure below the piston 18 will be exhausted through the pipe 20.', cavity 24 in the valve 22, and

exhaustiport 25. As the piston 18 moves ,downwardlytheblock 14, of course, will follow sothat the connection between the reach rod 10 and the arm 6 will be shifted to its lowerposition, and since .the point 43 is fixed the effect'of this motion'will be toforce the reversearm 6 to the position 6. When this 7 occurs the valve gear B. will be actuated by the reach rod 1 to. increase the cut-ofl' to a point sufficiently great for effecting starting of thelocomotiye.

The engineernow cracks his throttle in the .inanner customary. inthisart, and in, this connection it should berecalled. as previously pointedout, that when the locomotive is being startedxfull boiler pressure is never admittedto the cylinders by suddenly opening, the throttlewide. As a matter of fact, the engineer may actually open and close the throttle a slight distance a number, of times during thestarting process so asto avoid a tooi'sudden buildingup of full boiler. pressure in the cylinders. 7 With theparts in the position indicated and the cut-off lengthened as-described, there is. of course, at all times direct communica tion int o the cylinders through at least some of the main valve passages. In this. way the pressure of steam admitted to the steam chestscan always escape into the cylinders and the slack in th etrain is generally taken up in part, atleast by a pressureawhich is less than the, full boiler; pressure.

;,lj)uring, this period and-just as long as the ,pressureadmitted to the steam chest and t olthe cy linder isless than, say, 200 pounds,

.the valve45will remain open and the reverse arm remain in they position 6". :However, ust as soonas the train iswell started,

the engineer will, of course, open his throttle wide, at which time the pressure will rise above 200 pounds, compress the spring 51, open the valve 50, depress the piston 47, and

close the Valve 45, so that the air pressure can no longer reach the piston 30. When this occurs, the block 14, of course, will be returned to its upper position because the pressure on the upper side of the piston 18 will be exhausted through the pipe 21, cav-- ity 24, and exhaust passage 25, and live pressure will be admitted to the lower side of the piston 18 through the pipe 20.

This, of. course. will immediately return the reverse arm 6 from the position 6" to the 4 position 6 and the locomotive will then operate as a limited cut-off locomotive. It will be seen, therefore, that with my improved arrangement it is always possible to start thelocomotive because with the arm 6 in the position 6" the cut-off will be substantially that which is normal or customary in the art and sufiiciently long to insure a flow of steam to the cylinders regardless of the position of the cranks. Once a start has been made, the engine will continue to move no matter how quickly the pressure may build up above the limit suggested, viz. 200 pounds, because after a start has been made the locomotive will continue to operate even at a cut-off.

If the parts 37,f38, 39, and 40 are eliminated and the pipe 41 directly connected to the passage 42 shown in Fig. 2a, the operation will beslightly different, as follows: Such an arrangement would place the valve gear at all times under the control of the pressure in the valve chest so that whenever the pressure fell below 200 pounds the block 14 would be lowered from its upper position to its lower position and consequently the valve gear B through the connecting reach 1 rod 1 would be actuated to effect proportionately increasedcut-ofls throughout the entire range of movement of the reverse gear for either forward or backward movement. This method of operation is extremely valuable in cases where the boiler pressure for some reason or other has run down considerably because under these circumstances an engineer would automatically secure the benefit of greater cut-offs under conditions where with 50% or other limited cut-off the power of the engine would be materially reduced. To state the matter in other words, the increased cut-off at 200 pounds boiler pressure or less would be about equal to 50%cut-ofl' at 250 pounds boiler pressure, and, as stated,

by directly connecting the pipe 41 to the passageway '42, I can modify my device to atingmechanism, valve-reversing gear having connection thereto constructed to effect less than maximum valve cut-off when in full-gear position, and shiftable means for altering said connection to extend the cutoff for starting.

2. In a locomotlve having a cylinder and steam admission means therefor, valve-actuating mechanism, valve-reversing gear having connection thereto constructed to effect point.

3. In a locomotive having the usual cranks, the combination of a reverse gear, a valve gear, a connection between said gears includ ing means which is shiftable so as to increase or decrease the cut-0E, the normal position of said shiftable means being such as to provide a cut-off which is limited to a point substantially below that which is necessary to start the locomotive, and means for shifting said means so as to give a cut-off which is sufficiently increased to start the locomotive with the cranks in any position.

4. In a locomotive, the combination of a valve gear, a reverse gear, a connection between said gears which is shiftable so as to increase or decrease the cut-oil and means for shifting said connection to increase the cut-off when the reverse gear is moved to posltion for starting the locomotlve and to de crease the cut-off when the reverse gear is 'moved out of starting position.

5. In a steamlocomotive, the combination of a locomotive valve gear, a reverse gear connected thereto so that the cut-off is normally limited to a point substantially below the maximum necessary to start the locomotive, and means for changing the connection between the reverse gear and the valve gear so as to give a cut-off which is sufiiciently in creased to start the locomotive.

6. In a locomotive, the combination of a valve gear, a reverse gear, a shiftable connection between said gears normally giving a cut-off less than that which is necessary to start the locomotive, motor means for shifting said connection to increase the cut-off to a point suflicient to start the locomotive when the reverse gear isin position to start the locomotive, and a pilot device subject to the pressure of the steam being delivered to the locomotive steam chests for causing said motor means to shift said connection to establish saidnormal cut-off whenever said steam pressure is above a predetermined standard.

7. In a locomotive, the combination of a valve gear, a reverse gear, a shiftable connection between said gears normally giving a cut-off less than that which is necessary to start the locomotive and means for shifting said connection to increase the cut-off when the reverse gear is moved to full gear the reverse gear ismoved to full gear position for the purpose of starting the locomotive. A

9. In a locomotive, the combination of a reverse shaft, a reverse shaft arm, a reach rod for moving said arm, a valve gear, a second reach rod for connecting said arm to said valve gear, a connection between the first reach rod and said arm which is shiftable withrespect to its distance from the reverse shaft, means normally holding said connection at its greater distance from the reverse shaft, andmeans for bringing said connection inwardly to its lesser distance from the reverse shaft when the reverse shaft arm is moved to fullgear position for .the purpose of starting the locomotive.

- 10. In a locomotive, the combination ofa valve gear, a pivoted arm for controlling said valve gear, a reach rod for moving said arm having a connection with the arm which is movable with respect to its distance from the pivot,-and means for moving said connection closer to the pivot to increase the cut-off when starting the locomotive.

11. In a locomotive, the combination of a valve gear, a pivoted arm for. controlling said valve gear, a-reach rod for moving said arm having a connection with the arm which is movable with respect to its distance from the pivot, means for moving said connection closer to the pivot to increasethe cut-off when starting the locomotive, means for returning said connection to its original position, and a pilot device subject to steam chest pressure for causing said last-means to function when said pressurerises above a predetermined standard. 7 V 1 12. In a locomotive, the combination of a valve gear, a pivoted arm for moving said gear, a reach rod having a connection with said arm which is movable ,with respect to its distance from the pivot, aidouble acting piston for moving said connection, means normally supplying said piston with fluid pressure to hold the connection in its position farthest from the pivot, a valve forexhausting said first pressure and supplying the piston with pressure for moving the connection to its position closest to the pivot,

fluid pressure actuated means for moving said valve to efiect said last mentioned operation, and a normally closed valve for controlling said fluid pressure, said last valve being opened by said arm when said arm is moved to position for starting the locomotive.

13. The combination of a steam locomotive, a valve gear, a power reverse gear, a shiftable actuating connection between the valve gear and the power reverse gear capable of being moved so as to alter the cut-off while the position of the power reverse gear remains the same, the normal position of said actuating connection producing a cutofi' which is limited to a point substantially less than that which is necessary to start the locomotive, means for shifting said connection to produce a cut-01f which is suiiiciently long to start the locomotive when the power reverse gear is moved to full gear position, and means for reestablishing the limited cut ofi position when the power reverse gear is retracted from full gear position.

14. The combination of a steam locomotive, a valve gear, a power reverse gear, a shiftable actuating connection between the valve gear and the power reverse gear capable of being moved so as to alter the cut-off While the position of the power reverse gear remains the same, the normal position of said actuating connection producing a cutofl which is limited to a point substantially less than that which is necessary to start the locomotive, means for shifting said connection to produce a cut-ofi which is suificiently long to start the locomotive when the power reverse gear is moved to full gear position, and means for reestablishing the limited cutoff position when the power reverse gear is retracted from full gear position, together with pilot means which is subiect to the steam chest pressure for preventing the attainment of the aforesaid greater cut-ofl when the steam chest pressure is above a predetermined standard.

In testimony whereof I have hereunto signed my name.

WVILLIAM E. XVOODARD. 

